| X | − | 3 10 | X | − | 1 20 | X | − | 3 | = | 100 | + | 1 5 | × | 100 |
| Left side of the equation = | 13 20 | X | − | 3 |
13 20 | X | − | 3 | = | 100 | + | 1 5 | × | 100 |
| Right side of the equation = | 100 | + | 20 |
| = | 120 |
13 20 | X | − | 3 | = | 120 |
13 20 | X | = | 120 | + | 3 |
13 20 | X | = | 123 |
| X | = | 123 | ÷ | 13 20 |
| = | 123 | × | 20 13 |
| X | = | 2460 13 |
| X | = | 189.230769 |